Field of the Invention
Exemplary embodiments of the present invention relate to a control apparatus and method for improving fuel efficiency in a cooperative adaptive cruise control (CACC) active mode in a CACC system, and more particularly, to a control apparatus and method for improving fuel efficiency in a CACC active mode, which can improve the fuel efficiency through control of a vehicle speed so that a vehicle travels using an optimized cost in consideration of a target vehicle speed, a current speed of the vehicle, the minimum driving speed set in the vehicle, and a deceleration distance if the vehicle that uses the CACC system senses a forwarding vehicle and enters into the CACC active mode.
Description of the Related Art
An adaptive cruise control (hereinafter referred to as “ACC”) system is a system which operates to perform automated driving at a speed that is equal to or lower than that set by a driver and to maintain an inter-vehicle distance to a target vehicle that is equal to or larger than a predetermined distance. The ACC system provides a following function for maintaining the vehicle distance enough to prevent collision with a forward target vehicle, which is acquired by distance and/or position measurement sensors mounted on the vehicle, or a cruise function for performing automated driving at the speed set by the user.
The ACC system can enable the driver not to continuously operate an accelerator pedal in order to adjust the driving speed of the vehicle to provide convenience to the driver, and can achieve safety driving by maintaining the predetermined distance to the target vehicle and preventing the vehicle from driving over the set speed.
On the other hand, a CACC system is a system that can improve the ACC function through addition of V2X (Vehicle to Everything) communications to the above-described ACC system. The CACC system may receive the speed limit of a road through V2I (Vehicle to Infrastructure), receive information on a target vehicle that travels in the same lane through V2V (Vehicle to Vehicle), and then improve the ACC performance based on received information.
Recently, in association with a driving path setting system, such as navigation, which is positioned in the vehicle, the CACC system may set and use a target speed profile for improving the fuel efficiency in consideration of road information on the driving path.
In general, the CACC system operates to prevent collision with a target vehicle in a manner that it performs driving with the set target speed profile in the case where no target vehicle exists, and if the target vehicle is found or a forward vehicle is connected thereto, it performs deceleration driving to maintain a predetermined distance to the target vehicle. However, if the target vehicle is found and the vehicle deceleration is performed through braking in order to maintain a predetermined inter-vehicle distance, the driving is performed with a target speed profile that is different from the initially set target speed profile, and the speed of the subject vehicle is adjusted on the basis of the speed of the target vehicle. Accordingly, a stiff control in which acceleration/deceleration control is frequently performed may be performed to lower the fuel efficiency.